On 12/30/2015 12:35 PM, Ritesh Raj Sarraf wrote: > But the change you've proposed has other repercussion. It breaks > shutdown, because now, iscsi service/sessions are terminated way early. > This leaves, effectively, a hung sanboot system. > > Please see attached images. > > I also didn't like that iscsi shutdown, even thought my rootfs was > running. > > I'll keep digging.
Ok, so I think there's two things going on here: a problem in a change I made in that doesn't work in your specific configuration (which we should debug) and a general question about how to handle shutdown. First of all: the fact that iSCSI volumes are shut down is a change I made on purpose. There are two parts to this: first of all, iscsid is going to be killed anyway,[*] but the kernel will keep running sessions open regardless (unless there's an error with the connection / the target). Secondly, which is the change I did make, is that iSCSI sessions are logged out on shutdown regardless of whether the rootfs is on iSCSI. I did that because I think it is still correct to log out of sessions that the rootfs is NOT on, because we want to cleanly logout of anything that is possible to log out of. There is a flag in /etc/default/open-iscsi to return to the old behavior, this is also mentioned in the NEWS file, which is shown on updates, but not on new installs. Note that this does not include the rootfs sessions - they SHOULD be excluded. (Of course, if you disagree with this change and think ALL sessions, not just the rootfs sessions, should be kept open by default, we could discuss this separately.) Now for the problem in your case: there is code in the open-iscsi package in unstable that tries to make sure we don't close sessions where the rootfs is on. This consists of two steps: 1) /lib/open-iscsi/umountiscsi.sh [#] will try to umount filesystems on iSCSI. At the same time it detects sessions that contain the root filesystem and writes them out into the file /run/open-iscsi/shutdown-keep-sessions. 2) /lib/open-iscsi/logout-all.sh [~] will detect if the file /run/open-iscsi/shutdown-keep-sessions exists - and if it does it will *NOT* run the default iscsiadm -m node --logoutall=all but rather log out of all sessions that were not excluded. So what happens in your case is that umountiscsi.sh likely doesn't properly detect your setup where your rootfs is on iSCSI - and therefore doesn't exclude the relevant sessions from logout. To test this, you should run the /lib/open-iscsi/umountiscsi.sh script manually - that should *not* try to umount anything (because it should detect that it's the rootfs) and write out /run/open-iscsi/shutdown-keep-sessions. You should check that that file contains all the sessions that your rootfs relies on. Hope that gives you enough pointers to debug this. Regards, Christian [*] systemd tracks processes, so it's going to be killed. There is a possibility to avoid this, but this requires changes to iscsid and will be rather complicated to get the integration right. Not saying we shouldn't consider this, but just saying that's complicated, and is something that's much lower on my TODO list. [#] http://anonscm.debian.org/cgit/pkg-iscsi/open-iscsi.git/tree/debian/extra/umountiscsi.sh [~] http://anonscm.debian.org/cgit/pkg-iscsi/open-iscsi.git/tree/debian/extra/logout-all.sh
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